The former foreign secretary, Robin Cook, was facing attacks from his former cabinet colleagues over claims in his serialised diaries that Tony Blair went to war in Iraq knowing that Saddam Hussein had no viable weapons of mass destruction.
It is the first time that Mr Cook has accused Mr Blair of knowingly misleading parliament over the threat posed by Iraq, as opposed to making a grievous misjudgment. Until now, unlike his fellow former cabinet minister Clare Short, he has gone out of his way to insist he was not accusing Mr Blair of deception.
His harsher charge of deceit led to renewed calls from the Liberal Democrat foreign affairs spokesman, Menzies Campbell, for an independent inquiry into the government's decision to go to war.
In the main new allegation in the book, Mr Cook says he was given an intelligence briefing by the joint intelligence commitee chairman, John Scarlett, on February 20 that left him convinced that "Saddam probably does not have weapons of mass destruction in the sense that weapons that could be used against large scale civilian targets".
On the basis of this briefing, Mr Cook told the prime minister at a meeting on March 10 that he did not believe Saddam had weapons that could strike at strategic cities. Asked by Mr Cook whether he was worried Saddam could fire battlefield chemical weapons at British troops, Mr Blair replied: "Yes, but all the efforts he has had to put into concealment makes it difficult for him to assemble them quickly for use."
Mr Cook claims, on the basis of these exchanges, that both chairman of the JIC and Mr Blair had "assented" to his view that the Iraqis did not have long-distance strategic weapons, let alone chemical weapons capable of being fired within 45 minutes, the contro versial claim initially made by the government in the September 2002 intelligence dossier".
He writes: "I have no reason to doubt that Tony Blair believed in September 2002 that Saddam really had weapons of mass destruction ready for firing within 45 minutes. What was clear from this conversation was that he did not believe it himself in March this year."
Mr Cook then poses the question whether Mr Blair had a duty like other ministers to correct the record "as soon as they are aware they have misled parliament".
Mr Cook also suggests in the book that by the time the war became inevitable Mr Blair was a man "who was genuinely puzzled as to how he had got himself into his present dilemma. I suspect he had never expected to find himself ordering British troops into war without UN backing".
One cabinet minister dis missed the book as "pulp fiction" and others said Mr Cook had falsely portrayed them as opposing the war within cabinet. One said it was outrageous that he was being billed in the book as an opponent when all he had done was to ask sensible questions in cabinet a year before the war occurred.
Mr Cook is known to be sensitive to the charge that he is making up to £400,000 out of betraying private conversations, but regards his version of the war build-up as too important to suppress.
· A former chairman of the joint intelligence committee last night attacked the government's dossier on Iraq's banned weapons programme, branding it "a mistake".
Implictly criticising John Scarlett, current chairman of the committee, Sir Paul Lever said he would not have negotiated the dossier's text with No 10. He told Tom Mangold in a Channel 4 report on events leading to the death of the governmentweapons expert, David Kelly, that he might have resigned had he been placed under the same presssure as Mr Scarlett.
